1. Field of Invention
The present invention relates to a water-permeable resinous composition for road paving having high strength and adequate water-permeability for use in paving such as footpaths, driveways, parking lots, plazas.
The present invention also relates to a pavement of footpaths, driveways, and others, that uses thermosetting resins and as additives to obtain great strength and adequate water-permeability.
The present invention also includes water-permeable blocks for paving footpaths, composed of the aggregate, thermosetting resins, and additives for improvement of adhesion, to pave on the prior water-permeable concrete or asphalt layer.
More particularly, the present invention relates to a resinous composition for road paving that has high strength and permeability, and is composed of the aggregate, thermosetting resins, and cellulose or lignocellulose, or their derivatives as additives for improvement of the adhesion of the latter.
2. Background of Related Art
The rapid advance of modern industries and swift urbanization has caused an astounding increase in areas paved with asphalt, concrete, and various other types of paving composites. This increase of paved areas has in its turn brought about various problems because the rain water in the rainy season, unable to permeate into the soil, quickly drains away through the sewage system. The problems include, for example, (1) decrease of moisture of the ground which causes drainage of the land of underground water and the resultant retarding of the growth of roadside trees; (2) flooding of sewers at times even of an inconsiderable rainfall, water concentrating in the system at once; (3) higher of underground temperatures and insufficiency of oxygen speeding ecological changes; and (4) higher of summer time temperature in urban areas due to upon lessened radiation of the terrestrial heat; and others.
With a view to overcoming these problems water-permeable paving systems making use of water-permeable materials have been developed, including water-permeable asphalt and water-permeable concrete, and these are somewhat widely in use in paving footpaths, driveways, plazas, parking lots, and the like. But paving by the water-permeable asphalt has its own inherent problems: in the mid-day heat of hot summers the asphalt easily melts and the water-permeation holes clog, quickly reducing the water-permeation, while the holes and gaps inside the pavement increase in number enlarging the areas of the surface where water and air contact, thus hastening the aging of the asphalt itself (see Handbook on Water-Permeable Pavement, By Roadbuilding Association of Japan). The water-permeable concrete paving is known to aid the water-permeable asphalt paving in resistance against aging and the general strength, but its pavement surface easily erodes, is weak in shock resistance, and, its surface is rough with poorer elasticity, resulting in less comfort for the walker than the latter. In both of these two ways of paving the water-permeable paving material is invariable black or dull gray in color, monotonous in a word, and even when it is deliberately colored the color very easily fades or smudges, that is, they are either of them no way very suitable for paving sidewalks or passages for strollers in a park, if not from a particularly aesthetic point of view.
A solution to all these drawbacks of the water-permeable asphalt and water-permeable concrete paving is the paving with water-permeable resinous paving material, wherein the components of aggregate are put together tight by water-permeable resin. Paving with this water-permeable resinous paving material is not only better than the above-described water-permeable asphalt or water-permeable concrete paving in its water-proofing, antichemical, or anti-wear characteristics but in its such other physical properties as strength against compression, binding, and tension. This water-permeable resinous paving has advantages in that, even in extreme heat in summer, the reduction of strength is little, a small quantity of adhesive is required, and that good sense of beauty can be had because the synthetic resin is semi-transparent and so the natural color of a chosen color of color ceramic aggregate can be maintained as it is.
However, the thermosetting resin used in the water-permeable resinous paving system is rather expensive, and thus the system rather lacks in economic feasibility. Because of this expensiveness of the resin it is only sparingly used, or else the layer of the paving is made as thin as possible.
In fact, water-permeable resinous paving has typically had only as little as 20 mm or less of thickness, hardly sufficient. A layer so thin is merely paved on the top of water-permeable asphalt or water-permeable concrete, resulting in a difficulty in actual paving work (Japan's Patent Laid-Open Gazette Hei-3-169901). Because of such a drawback as this the water-permeable resinous paving is made use of only in paving footpaths, which do not usually require particularly great strength, and not used in paving driveways, which invariably require great strength of a pavement.
The inventors of the present invention have come to develop a new high-strength water-permeable resinous paving composition which can be used in paving driveways, which has great strength, which uses a small quantity of resin. This invention resolves those problems set forth above of the water-permeable asphalt or water-permeable concrete paving of prior arts.
The objective of the present invention is to provide a resinous composition for road paving which has both high strength and good water-permeability.
Another objective of the present invention is to provide a high strength water-permeable composition for road paving which, even if only a small quantity of resin is used in a thin layer, still has a sufficient strength and good water-permeability for paving driveways also.
Still another objective of the present invention is to provide a road pavement formed by way of paving footpaths, driveway, parking lots, plazas, and the like. With resinous paving material being used to ensure that a paved surface having a high strength and good water-permeability is given over the base of a road.
Yet another objective of the present invention is to provide water-permeable road blocks to form a water-permeable resinous pavement layer over the water-permeable asphalt of concrete layer of footpaths.